In this proposal, we request a second renewal of our Chemistry-Biology Interface (CBI) Predoctoral Training Grant. In 1995 we launched a new interdisciplinary training program at the University of Massachusetts that built on existing strengths and formalized the faculty's commitment to collaboration between the physical and life sciences. We implemented a CBI curriculum that meshed with the requirements of the three participating graduate programs, Chemistry, Molecular &Cellular Biology, and Polymer Science &Engineering, yet enabled students with either chemical or biological backgrounds to supplement training in their home discipline with training in the complementary discipline. During the current funding period, our CBI Training Program has grown substantially: the number of participating departments has grown from 3 to 4, the number of CBI Training Faculty has grown from 16 to 19 and most notably, the number of formally affiliated students has increased from 14 to 61. The addition of Chemical Engineering builds our strengths in quantitative training and in biomaterials, and adds new opportunities in bioengineering. We anticipate continued growth of our CBI Program as additional departments, notably Physics and Computer Science, move into CBI-related areas. The CBI Program currently provides NIH support for six predoctoral students, and a University match supports one additional graduate student working at the chemistry-biology interface. To continue to foster the growing strength of the CBI program as it expands into new disciplines and trains increasing numbers of students, we request a modest increase in the number of NIH-funded Traineeships in years 3-5 of the of the grant period. The interdisciplinary training we provide is exemplified by the development of a new "Drug Design" course that is now an integral part of the CBI curriculum. In this popular course, students are provided with background lectures in chemistry and biology to bring them to a common ground, followed by weekly seminars by speakers from the pharmaceutical industry to introduce students to the full range of topics in chemistry and biology that are critical for successful design and development of new drugs. With this type of training in the methods and intellectual framework of both chemistry and biology, our CBI graduates are equipped to pose and solve significant biomedical questions in their future work.